This invention relates generally to a closure for connecting a manually actuated liquid dispenser to a container upon threading the closure to the container neck finish, mutually engaging ratchet teeth on the closure and neck finish serving to positively lock the closure in place. More particularly, the ratchet teeth inside the closure are specifically designed to force the closure down on the container upon attempts to unscrew the closure.
Many manually actuated dispensers of the pump actuated type, for example, are thread mounted on plastic containers for dispensing of a wide variety of liquid products. Many products such as paint removers, oven cleaners, insecticides, etc. could be harmful if improperly used.
Non-removable closures for connecting the dispensers to the container have been devised utilizing a ratchet system for locking the closure to the container neck finish to prevent removal of the dispenser upon unscrewing the closure.
U.S. Pat. No. 4,345,691 discloses a child resistant bottle closure providing ratchet teeth inside the closure in engagement with ratchet teeth on the outside of the container neck finish to prevent the cap and pump from being removed from the container upon unscrewing the closure. The closure ratchet teeth and the neck finish ratchet teeth have mutually engagable trailing faces which extend radially and lie in planes containing the central axis of the closure. And, the ratchet teeth inside the closure are mutually spaced apart.
Such a ratchet system and others of the prior art can, however, fail upon application of sufficient torque on the cap in the unscrewing direction as caused by plastic deformation between the engaged ratchet teeth faces thereby decreasing the retention capability of the ratchet system.